Learning from the past is important for our characters, indeed it is more than that. It is vital. A real story has something happen to a character and the tale is in how that character handles that event. Do they develop and learn and go on to better things? Or do they refuse to learn and disaster strikes?
Anyone with any sense will learn from their mistakes, if only to try to avoid repeating them. So how do your characters do this? What do they learn? How do they apply it? When the potential for the same mistake comes up again (as it so often does in life), do they make the same mistake again or avoid it? See Groundhog Day as a great film example of this.
The past of course can be the character's own, the history of their setting (local, national and/or global), the history of their family or any combination of those things. But characters, if they are going to develop and be fully rounded, must make mistakes (it is how anyone learns anything of real value after all) and learn from those errors. And of course exploring the character's past and how it affects them now offers up all sorts of classic story ideas.